Resonator regulator



P 1968 P. ALTENBURGER 3,400,283

RESONATOR REGULATOR Filed Nov. 2'6, 1965 at? T W 1 M i o 4 L I WW A I J5 i ii H I q 2 II I I I I "4 1 Lil- I I 3 d 4 x F KB. I

I N VEN TOR. PAUL ALTENBURGEQ Arron/era.

United States Patent 3,400,283 RESONATOR REGULATOR Paul Altenburger,Besancon, Donbs, France, assignor to The United States Time Corporation,Waterbury, Conn., a corporation of Connecticut Filed Nov. 23, 1965, Ser.No. 509,266 4 Claims. (Cl. 310-36) ABSTRACT OF THE DISCLOSURE Anelectric watch includes a mechanical resonator unit. The unit consistsof two vibratory masses which are driven simultaneously in short arcs inopposite directions about a common axis. An elongated adjustment memberfrictionally engages a pin on one of the masses. The adjustment membermay be turned, its movement occurring in a plane parallel to the planesof vibration of the masses.

The present invention relates to timekeeping devices and moreparticularly to an adjustment device for a mechanical torsionalvibratory unit in an electric watch.

The mechanical vibratory unit described in U.S. Patent No. 2,939,971 toHolt may be applied to various frequency dependent devices. In the Holtpatent two annular vibrating elements are secured to a hub by radialflat springs and are driven simultaneously in opposite rotationaldirections about a common axis. The assembly, when excited, is a sourceof low frequency energy at constant frequency. The assembly isrelatively insensitive to shock and vibration.

In one application of the Holt invention to a watch, the vibrationelements are discs (resonators) arranged on either side of a base plateand suspended on radially spaced flat spring members so that the discsare capable of rotary vibration in opposite directions about a commonaxis through a limited arc. The spring members provide a restoringforce. The driving force is provided by an electromagnetic coil affixedto one disc which periodically repels a magnetic element atfixed to theother disc. The discs oscillate in resonance at a low frequency. Thevibratory element can supply its constant frequency information to atrain of gears or to electrical counting devices by mechanical pawls orby changing an electrical circuit parameter such as inductance orcapacitance.

It is the objective of the present invention to provide an inexpensiveand simple means by which frequency adjustment of a vibratory assemblymay be effected.

In accordance with this objective, I have provided a two-mass torsionalvibratory unit having an adjustment piece or regulator. The regulator isa small weight fixed to the vibratory unit and turna-ble about a pivot.Turning of the regulator varies its center of gravity, which changes themass moment of inertia of the vibrating mass, thereby adjusting thefrequency of vibration.

Other objectives of the present invention will be apparent from thedescription of the preferred embodiment of the invention set forthbelow, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a mechanical vibratory unit having thefrequency adjusting means of the present invention; and

FIGURE 2 is an enlarged plan view of the adjustment regulator.

The mechanical vibratory unit illustrated in FIGURE 1 comprises similarresonator masses 1 and 3 positioned on either side of base plate 2. Themasses are suspended by means of fiat spring elements 5, a first part ofwhich is fixed by means of pin 4 to the resonator 1, a second part ofthe spring is fixed to the base plate 2 and a third 3,400,283 PatentedSept. 3, 1968 par-t is fixed to resonator 3 in the same manner as thefirst part. These spring elements suspend resonators 1 and 3 from baseplate 2 and allow limited arcuate vibratory motion of the resonatorswith respect to the base plate 2. The resonators are drivensimultaneously in opposite directions. The springs 5 supply thetorsional restoring force of the system and mechanical or magnetic means(not shown) are employed to drive the resonators in opposite directions.The constant frequency vibration thus established is used to regulatethe frequency of an electrical circuit or to directly drive the geartrain of a watch or clock.

The general expression for a two-disc torsional vibratory system iswhere f is the resonant or natural frequency, K is the torsionalstiffness of the suspension, and I is the mass moment of inertia of onedisc, and I is the mass moment of inertia of the other.

For simple systems where the mass moments of inertia are the same forboth discs, the expression becomes Since K is a constant term, theexpression reduces to 1 K a r It is desirable to be able to adjust thefrequency of such vibrating systems to a standard frequency fortimepressions that an increase of mass moment of inertia will reduce thefrequency of the system.

The mass moment of inertia I for the revolving mass can be determinedfrom the expression Where r is the radius and dM is the incrementalmass. The mass moment of inertia is increased by increasing the radiusat which the mass is found. Such an increase in mass moment of inertiawill lower the resonant frequency of the vibrating system.

Adjustment of the natural frequency at which the vibratory systemresonates is effected by means of an eccentric regulator 6 which isfrictionally fitted to a pin 7 on resonator 1. Regulator 6 is adjustedby being swung about pin 7. Since the regulator is eccentric withrespect to pin 7, its rotation moves its center of gravity radially tothe resonator 1. Moving the adjustable regulator outwardly, toward the Ron scale 8, moves its center of gravity radially outward. Such movementincreases the mass moment of inertia of the resonator 1, and lowers thefrequency of vibration of the system. In contrast, moving the adjustableweight 6 inwardly about pin 7, toward the A- on scale 8, reduces themass moment of inertia and raises the frequency of vibration.

The regulator 6 is shown in FIGURE 2. The bore 10 is a tight fit for thepin 7. The slot 11 allows for spring grip of bore 10 about pin 7. Thisconstruction permits the regulator 6 to be rotated about pin 7 butprevents unintentional rotation. Alternatively, lock screws or the likemay be employed for greater security against such unintentional motion.

It will be apparent that modifications may be made within the scope andspirit of my invention and, accordingly, I do not wish to be limitedotherwise than as indicated by the terms of the appended claims. Forexample, each of the two resonators 1 and 3 may each have one of theregulators 6.

I claim:

1. The combination of an adjustment device and a mechanical vibratoryunit, said vibratory unit comprising two masses suspended from a basesuch that the said masses are capable of vibrating simultaneously inopposite directions to each other, said adjustment device comprising aregulator pivoted on one of the said masses and adapted to be fixed atdiiferent angles of its movement, the said regulator being eccentricallymovable in a plane parallel to the planes of vibratory motion of thesaid masses, said adjustment device being an elongated member having abore near one end and said bore frictionally engaging a pin on one ofthe said masses.

2. The combination as claimed in claim 1, wherein 3. The combination asclaimed in claim 1, "wherein each mass has an adjustment device.

4. The combination as claimed in claim 1, wherein the mass has anangular scale toward which said elongate 5 member points to indicate theextent of adjustment.

References Cited UNITED STATES PATENTS Re. 26,209 5/1967 Bennett et al.3l0-25 2,939,971 6/1960 Holt 31015 2,952,117 9/1960 Reese et a1. 58-48MILTON HIRSHFIELD, Primary Examiner.

said device has a slot extending from said end to said 15 D GGANAssistant Examiner bore to provide a spring grip on said pin.

